Transport Layer Security (TLS) is a cryptographic protocol that provides communication security over the Internet. The TLS protocol includes the capability of running a compression algorithm prior to encryption on the sender side and running the corresponding decompression algorithm after decryption on the receiver side. Compression is not important in every scenario, but it is useful for constrained bandwidth links such as 3G/4G wireless communication. Datagram Transport Layer Security (DTLS) is a datagram version of TLS. The User Datagram Protocol (UDP) provides very few error recovery services, offering instead a direct way to send and receive datagrams over an IP network. UDP is therefore referred to as an unreliable transport. The compression used by TLS cannot be applied to DTLS since it does not use a reliable transport to ensure the delivery of application datagrams that are protected by DTLS, and therefore, packet loss or reorder can interfere with proper operation of the decompressor.
Internet Protocol Security (IPsec) is a protocol for securing Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a communication session. IPsec provides stateless compression in which each packet is independently compressed. However, this method is inefficient because individual packets do not contain very much redundancy.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.